Abel and Cain

The Mahometan tradition of the death of Abel is this: Cain was
born with a twin sister who was named Aclima, and Abel with a twin
sister named Jumella. Adam wished Cain to marry Abel's twin sister, and
Abel to marry Cain's. Cain would not consent to this arrangement, and
Adam proposed to refer the question to God by means of a sacrifice. God
rejected Cain's sacrifice to signify his disapproval of his marriage
with Aclima, his twin sister, and Cain slew his brother in a fit of
jealousy.